Efficient degradation of organic pollutants by S-NaTaO3/biochar under visible light and the photocatalytic performance of a permonosulfate-based dual-effect catalytic system

Removing large concentrations of organic pollutants from water efficiently and quickly under visible light is essential to developing photocatalytic technology and improving solar energy efficiency. This study used a simple hydrothermal method to prepare a non-metallic, S-doped NaTaO₃ (S-NTO) photocatalyst, which was then loaded onto biochar (BC) to form a S-NTO/BC composite photocatalyst. After uniform loading onto BC, the S-NTO particles transformed from cubic to spherical. The photogenerated electron-hole pair recombination probability of the composite photocatalyst was significantly lower than those of the NTO particles. The light absorption range of the catalyst was effectively widened from 310 nm UV region to visible region. In addition, a dual-effect catalytic system was constructed by introducing peroxymonosulfate (PMS) into the environment of the pollution to be degraded. The Rhodamine B, Methyl Orange, Acid Orange 7, tetracycline, and ciprofloxacin degradation efficiency at 40 mg/L reached 99.6%, 99.2%, 84.5%, 67.1%, and 70.7%, respectively, after irradiation by a 40 W lamps for 90 min. The high-efficiency visible-light catalytic activity of the dual-effect catalytic system was attributed to doping with non-metallic sulfur and loading of catalysts onto BC. The development of this dual-effect catalytic system provides new ideas for quickly and efficiently solving the problem of high-concentration organic pollution in aqueous environments, rationally and fully utilizing solar energy, and expanding the application of photocatalytic technology to practice.     

掺硫改性TiO2对活性艳红X-3B的光催化降解性能研究

以硫脲为硫的源物质,以钛酸四丁酯为TiO₂的前驱体,采用溶胶-凝胶法制备了掺硫改性TiO₂光催化剂。以活性艳红X-3B为目标污染物,研究了该催化剂的光催化降解性能,对硫掺杂量、催化剂焙烧温度、溶液pH值以及催化剂添加量等影响因素进行了研究,并采用XRD分析手法对光催化剂进行表征。结果表明,经掺硫改性后的TiO₂的催化活性有了很大提高,且硫的掺杂有一个最佳值,即Ti∶S的摩尔比为1∶1。经掺硫改性的TiO₂在可见光区具备一定的催化活性, 180 min内对活性艳红X-3B的去除率可达35.1%,且在紫外光区的催化活性优于纯TiO₂。     

固相反应两步法制备掺硫TiO2及降解聚丙烯酰胺

以偏钛酸、硫脲为原料,第一步采用低热固相反应法合成含硫氧化钛前驱体,第二步经中温(400、500、600℃)灼烧制得TiO2-xSx粉末晶体。用XRD、SEM、XPS对制备的粉体结构、形貌和组成进行表征。通过对聚丙烯酰胺(PAM)降解实验,研究TiO2-xSx在太阳光照下的光催化性能,并通过正交试验研究了油田回注水中聚丙烯酰胺(PAM)的最佳降解条件。结果表明,用该方法制备的掺硫氧化钛相转变温度明显降低;在降解PAM的实验中表现出良好的可见光催化活性,比未掺杂TiO2的降解率提高了1.2倍。硫掺杂TiO2处理聚丙烯酰胺的最佳条件为温度40℃、pH=3、催化剂投加量为0.3g、氧化时间90min,COD去除率达到69.5%。     

太阳光/硫掺杂TiO2体系对双酚A的氧化性能研究

利用小试试验研究了太阳光和硫(S)掺杂TiO2体系对水中双酚A(BPA)的降解效能及影响因素.结果表明,太阳光/S掺杂TiO2体系对纯水中BPA的去除效能较太阳光/TiO2体系显著提高,30 min时的去除率分别为79%和49%,且两体系对BPA的降解过程均很好地符合拟一级反应动力学模型;H2O2的投加量对两体系氧化BPA的性能均有显著的影响,但其最佳投加量不同(两体系的最佳H2O2浓度分别为20 mg/L和15 mg/L,太阳光/S掺杂TiO2比太阳光/TiO2体系高5 mg/L);较低的pH值有利于两体系中BPA的降解,pH为5.5时的反应速率常数比pH为8.5时高50%左右;腐殖酸会不同程度的降低两体系对BPA的降解速率,其影响均可以用二次方程来表示.此外,腐殖酸对太阳光/S掺杂TiO2体系的弱化作用要明显强于对太阳光/TiO2体系的,原因在于腐殖酸不仅会与BPA分子竞争.OH,而且会吸收部分可激发TiO2产生.OH的可见光.     

太阳光/硫掺杂Tio2体系对双酚A的氧化性能研究

利用小试试验研究了太阳光和硫(s)掺杂Tio₂体系对水中双酚A(BPA)的降解效能及影响因素.结果表明,太阳光/S掺杂Tio₂体系对纯水中BPA的去除效能较太阳光